Origin of the volcanic-hosted Yamansu Fe deposit, Eastern Tianshan, NW China: constraints from pyrite Re-Os isotopes, stable isotopes, and in situ magnetite trace elements

2018 ◽  
Vol 53 (7) ◽  
pp. 1039-1060 ◽  
Author(s):  
Xiao-Wen Huang ◽  
Mei-Fu Zhou ◽  
Georges Beaudoin ◽  
Jian-Feng Gao ◽  
Liang Qi ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Trace Elements ◽  
Eastern Tianshan ◽  
Nw China ◽  
Os Isotopes

scholarly journals Mineralization of the Tuwu Porphyry Cu Deposit in Eastern Tianshan, NW China: Insights From In Situ Trace Elements of Chlorite and Pyrite

2021 ◽  
Vol 9 ◽  
Author(s):  
Wei Tan ◽  
Qigui Mao ◽  
Mingjie Yu ◽  
Yan Sun ◽  
Xiaoqiang Lv
Keyword(s):  
Rare Earth ◽  
Trace Element ◽  
Earth Element ◽  
Distribution Patterns ◽  
Eastern Tianshan ◽  
Nw China ◽  
Ree Distribution ◽  
Lree Enrichment ◽  
Stage Stage

The Tuwu porphyry copper deposit is located on the Dananhu-Haerlik island arc in eastern Tianshan, NW China. Based on geology, petrology, and in situ trace element studies of pyrite and chlorite, we redefined the characteristics of hydrothermal fluids and the following three mineralization stages: premineralization stage (stage Ⅰ), porphyry metallogenic stage (stage Ⅱ), and superimposed transformation stage (stage Ⅲ). Pyrite stage Ⅰ (Py-I) has the highest Co/Ni ratios, and the precipitation crystallization of chlorite (Chl-I2) has the similar rare earth element distribution patterns with those of volcanic rocks Carboniferous Qieshan (CQ), indicating intense volcanic hydrothermal activity. The Co/Ni ratios of Py-II1 and Py-II2 (stage Ⅱ) tend to decrease over time. Moreover, the rare earth element (REE) distribution patterns of Chl-II have similar LREE enrichment, and the Eu anomalies in Chl-II1, Chl-II2, and Chl-II3 range from positive to negative. The initial ore-forming fluid was mainly magmatic hydrothermal fluid, and with the late-stage addition of meteoric water and continuous sulfide precipitation, the trace element composition of the fluid changed, and the whole system became more oxidizing. Py-III (stage Ⅲ) has the lowest Co/Ni ratios, and the REE distribution pattern of Chl-III is characterized by LREE enrichment. Moreover, the Chl-III shows obvious shear deformation characteristics. The results indicate that the host rocks experienced intensely superimposed reformation. By combining and integrating our results with the regional evolution processes in the eastern Tianshan, we propose that the Tuwu porphyry deposit has undergone magmatic hydrothermal and metamorphic hydrothermal processes. Volcanism (stage Ⅰ) provided the space and initial conditions for the emplacement of the metallogenic body. With the emplacement of the plagiogranite porphyry (stage Ⅱ), the main copper mineralization occurred in the porphyry and surrounding rocks. After porphyry mineralization (stage Ⅲ), regional ductile shearing and collisional compression led to a copper reaction, and its accumulation along the faults formed an ore shoot.

Ore genesis of the Duotoushan Fe-Cu deposit, Eastern Tianshan, NW China: Constraints from ore geology, mineral geochemistry, fluid inclusion and stable isotopes

2018 ◽  
Vol 100 ◽  
pp. 401-421 ◽  
Author(s):  
Weifeng Zhang ◽  
Huayong Chen ◽  
Lianhong Peng ◽  
Liandang Zhao ◽  
Wanjian Lu ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Fluid Inclusion ◽  
Ore Genesis ◽  
Eastern Tianshan ◽  
Nw China

scholarly journals Petrogenesis and Tectonic Significance of the ~276 Ma Baixintan Ni-Cu Ore-Bearing Mafic-Ultramafic Intrusion in the Eastern Tianshan Orogenic Belt, NW China

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 348
Author(s):  
Minxin You ◽  
Wenyuan Li ◽  
Houmin Li ◽  
Zhaowei Zhang ◽  
Xin Li
Keyword(s):  
Orogenic Belt ◽  
Olivine Gabbro ◽  
Early Permian ◽  
Eastern Tianshan ◽  
Nw China ◽  
Tianshan Orogenic Belt ◽  
Tectonic Significance ◽  
Ultramafic Intrusion ◽  
Back Arc ◽  
Duke Island

The Baixintan mafic-ultramafic intrusion in the Dananhu-Tousuquan arc of the Eastern Tianshan orogenic belt is composed of lherzolite, olivine gabbro, and gabbro. Olivine gabbros contain zircon grains with a U-Pb age of 276.8 ± 1.1 Ma, similar to the ages of other Early Permian Ni-Cu ore-bearing intrusions in the region. The alkaline-silica diagrams, AFM diagram, together with the Ni/Cu-Pd/Ir diagram, indicate that the parental magmas for the Baixintan intrusion were likely high-Mg tholeiitic basaltic in composition. The Cu/Pd ratios, the relatively depleted PGEs and the correlations between them demonstrate that the parental magmas had already experienced sulfide segregation. The lower CaO content in pyroxenites compared with the Duke Island Alaskan-type intrusion and the composition of spinels imply that Baixintan is not an Alaskan-type intrusion. By comparing the Baixintan intrusion with other specific mafic-ultramafic intrusions, this paper considers that the mantle source of the Baixintan intrusion is metasomatized by subduction slab-derived fluids’ components, which gives rise to the negative anomalies of Nb, Ti, and Ta elements. Nb/Yb-Th/Yb, Nb/Yb-TiO2/Yb, and ThN-NbN plots show that the Baixintan intrusion was emplaced in a back-arc spreading environment and may be related to a mantle plume.

Correlation of Grassy Lake and Cedar Lake ambers using infrared spectroscopy, stable isotopes, and palaeoentomology

2008 ◽  
Vol 45 (9) ◽  
pp. 1061-1082 ◽  
Author(s):  
Ryan C. McKellar ◽  
Alexander P. Wolfe ◽  
Ralf Tappert ◽  
Karlis Muehlenbachs
Keyword(s):  
Stable Isotopes ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Late Cretaceous ◽  
Western Canada ◽  
Long Distance ◽  
Geochemical Fingerprinting ◽  
Long Distance Transport ◽  
Distance Transport

The Late Cretaceous Grassy Lake and Cedar Lake amber deposits of western Canada are among North America’s most famous amber-producing localities. Although it has been suggested for over a century that Cedar Lake amber from western Manitoba may be a secondary deposit having originated from strata in Alberta, this hypothesis has not been tested explicitly using geochemical fingerprinting coupled to comparative analyses of arthropod faunal content. Although there are many amber-containing horizons associated with Cretaceous coals throughout Alberta, most are thermally mature and brittle, thus lacking the resilience to survive long distance transport while preserving intact biotic inclusions. One of the few exceptions is the amber found in situ at Grassy Lake. We present a suite of new analyses from these and other Late Cretaceous ambers from western Canada, including stable isotopes (H and C), Fourier transform infrared (FTIR) spectra, and an updated faunal compendium for the Grassy and Cedar lakes arthropod assemblages. When combined with amber’s physical properties and stratigraphic constraints, the results of these analyses confirm that Cedar Lake amber is derived directly from the Grassy Lake amber deposit or an immediate correlative equivalent. This enables the palaeoenvironmental context of Grassy Lake amber to be extended to the Cedar Lake deposit, making possible a more inclusive survey of Cretaceous arthropod faunas.

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